<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>day02_homework</title>
    <link rel="stylesheet" href="style.css">
    <style>
        .div{width: 200px; height: 200px;}
        #div1{border:1px solid black;}
        #div1 div{
            width: 100px;
            height: 100px;
        }
        .div1{position: relative}
        .div2{position: relative;margin: -200px 0 0 100px}
        .div3{position: relative;margin: 0 0 0 100px}

        #div1 div:nth-child(1){background-color: pink}
        #div1 div:nth-child(2){background-color: lightgoldenrodyellow}
        #div1 div:nth-child(3){background-color: aqua}
        #div1 div:nth-child(4){background-color: darkorchid}
    </style>
</head>
<body>
    <div id="div1" class="div">
        <div class="div1"></div>
        <div class="div1"></div>
        <div class="div2"></div>
        <div class="div3"></div>
    </div>
</body>
</html>